Technical Field
The present invention relates to a device for filling at least one container with a fill product, and a method for filling a container with a fill product using such a device.
Related Art
In filling devices for filling a fill product into containers, in particular in the field of filling and dosing machines for fluid or viscous foodstuffs such as for example beverages, it is known to make the fill product available in a product reservoir, from which the actual filling elements for filling the containers with the fill product are supplied. Product reservoirs are known for example in the form of a tank, a ring bowl or a central bowl of a rotary filling machine, and are usually provided at a level above the filling elements. In normal operation of a rotary filler, the product reservoir rotates together with the filling elements that are disposed upon it, in order thereby to enable continuous filling of containers that are successively supplied for filling.
The filling elements that are provided can be either piston filling elements, which enable the handling of fill product at underpressure and overpressure, or filling elements from which the fill product flows under its own weight. Piston fillers are usually used for high viscosity fill products such as cream, ketchup or baby food.
With fill products containing particles, it can occur that the different phases of the fill product separate in the filling and dosing machine, for instance if the particles have a tendency to sink lower or float upwards. Examples of such fill products containing particles are milk products with fruit components, or juices with fruit pulp. In order to avoid such separation or division of product components, a motor-driven stirring device is used, which is integrated in the product reservoir and permanently immersed in the product reservoir. This can be achieved, for instance in the case of foodstuff filling using a piston doser in a rotary-type process, either by means of motorized stirring devices or by means of fixed mixers, which protrude permanently into the fill product from a non-rotating part of the machine into the rotating product reservoir that is filled with product. Such a mixer thus serves during the rotational movement of the product reservoir to mix the fill product, and inhibits the rapid separation of components of the product that is to be filled, thus providing consistent product quality.
DE 10 2012 104 275 A1 describes a device for filling containers, which has such a mixer. The mixer is implemented as a fixed agitator blade, permanently immersed in the fill product. Such a fixed agitator blade, permanently immersed in the fill product, is also disclosed in DE 10 2010 031 873 A1.
The disadvantage of such devices is that the permanent stirring of the fill product increases the risk of bubble formation, foam formation and/or mechanical stressing of the fill product, which in the case of certain fill products can lead to reduction of the accuracy of filling and/or to deterioration in the quality of the filled fill product.
As well as the above-mentioned problems, which result from the permanent mechanical mixing of the fill product, a further problem exists in conventional filling and dosing machines, in that if operation is interrupted for any reason the fill product undergoes a change in temperature, such that its temperature may no longer lie within the temperature range required for filling.
This is because in many applications the temperature of the product that is to be filled is controlled for microbiological reasons (for instance in the case of the hot filling of juices) or for reasons of processability in the case of foodstuffs that are viscous or whose texture changes with temperature (for example when filling fruit jellies or jams).
In DE 10 2012 104 275 A1, the temperature is controlled by means of a heat exchanger provided in the product reservoir. Specifically, the temperature control of the product is carried out, for example, by means of a double-walled product reservoir through which cooling or heating medium flows, or alternatively by means of heating coils attached to the fixed part of the device, which are permanently immersed in the fill product in the product reservoir.
When the temperature of the dosed product is controlled in the rotating product reservoir by means of heating or cooling jackets, the design requires an elaborate and costly means of supplying and discharging cooling or heating medium (for example warm or cold water, or steam). This involves additional expense in terms of process control and equipment. Fixed temperature control elements that are permanently immersed in the rotating product reservoir (for example a heating coil) are also suboptimal from the cleaning point of view.
To summarize, in the state of the art two problem areas may be identified in devices for filling containers that have a rotatable product reservoir: a) problems resulting from the permanent mixing of the fill product, and b) problems in connection with the temperature control of the fill product.